1. Field of the Invention
The present invention relates to a flat panel display device and fabrication method thereof.
2. Background of the Related Art
An insulating layer is essential for fabricating a flat panel device.
In flat panel displays, an organic EL (electroluminescent) device emits a light in a manner that electric charges are injected into an organic layer between an electron injection electrode(cathode) and a hole injection electrode(anode), electrons and holes are paired, and the resulting pairs emit light. The EL device is driven by a low voltage and consumes less power.
In this case, an insulating layer is formed on a substrate so as to cover the edges of the anode which are vulnerable during the fabrication process.
When the edges of the anode are damaged, the cathode and anode are easily shorted. Once the cathode and anode are shorted, the organic layer between the cathode and anode is damaged. Thus, the ELD device fails to emit light normally.
Insulating layers are mainly divided into inorganic insulating layers and organic insulating layers. The inorganic insulating layers include oxide, nitride and the like, while the organic insulating layers include polyimide, polyacryl, photoresist and the like.
However, the use of inorganic insulating layers requires highly expensive equipment. Therefore, organic insulating layers have greater merit using a conventional PR (photoresist) line for fabrication.
An organic insulating layer in a display device is formed on glass or ITO (indium tin oxide). Namely, patterns of the organic insulating layer are defined on the glass including the patterned ITO. The ITO includes auxiliary electrodes such as a bus electrode and the like.
Such a process, as shown in FIG. 1 and FIG. 2, of defining an organic insulating pattern results in disadvantages. Most organic insulating layers have excellent adhesion to ITO but poor adhesion to glass. When organic insulating layer patterns are developed, the patterns at the ITO side remain intact but those at the glass side peel off.
As mentioned in the above explanation, a flat panel device according to the related art brings about problems/disadvantages such as residues of an organic insulating layer during a patterning process, poor shapes of inorganic insulating layer patterns, and the like, thereby degrading characteristics such as device performance, endurance and the like.
Accordingly, the present invention is directed to a flat panel display device and fabrication method thereof that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a flat panel display device and fabrication method thereof which eliminates the peeling of an insulating layer.
The present invention, which is characterized in that at least one auxiliary pattern, as well as lower electrodes, is formed on an edge of a substrate of a flat panel display so as to overlap with an insulating layer, preventing peeling of the insulating layer from the substrate.
Moreover, the adhesion between the auxiliary pattern and insulating layer is superior to that between the substrate and insulating layer, whereby the present invention enables the peeling of an insulating layer from a substrate to be greatly reduced.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a flat panel display device according to the present invention includes a lower electrode area formed on a substrate and defining luminescent pixels, at least one auxiliary pattern formed on at least one edge area of the substrate so as to be separated from the lower electrode area, and an insulating layer formed on an area excluding the luminescent pixels so as to be overlapped in part with at least one auxiliary pattern.
In another aspect of the present invention, a flat panel display device includes a plurality of lower electrodes extending on a substrate in one direction, a plurality of luminescent pixels formed on and defined by the lower electrodes, a plurality of connection tabs formed on one edge of the substrate in a direction crossing with the extending direction of the lower electrodes so as not to overlap the lower electrodes, an insulating layer formed on an area excluding the luminescent pixels and the lower electrodes, at least one auxiliary pattern formed at an edge area of the substrate so as to overlap at least in part with the insulating layer to prevent the insulating layer from peeling, and an upper electrode formed over the lower electrodes so as to make contact with the connection tabs.
Preferably, the device further includes at least a second auxiliary pattern between the lower electrodes and connection tabs, respectively, so as to at leat partially overlap with the insulating layer. In this case, the distance is similar to that between the adjacent pixels in the direction crossing with the extending direction of the lower electrodes, thereby preventing a leakage current.
In a further aspect of the present invention, a method of fabricating a flat panel display device includes the steps of forming a plurality of lower electrodes on a substrate so as to extend in one direction wherein luminescent pixels are defined over the lower electrodes, forming a plurality of connection tabs on one edge of the substrate in a direction crossing with the extending direction of the lower electrodes so as to not overlap the lower electrodes, and forming at least one auxiliary pattern on an edge area of the substrate, forming an insulating layer on an area excluding the luminescent pixels and the lower electrodes, so as to at least partially overlap at least one auxiliary pattern, and forming an upper electrode over the lower electrodes so as to make contact with the connection tabs.
As mentioned in the above explanation, the present invention, which is characterized in that at least one auxiliary pattern as well as lower electrodes are formed on a substrate, prevents the peeling of the insulating layer from the substrate.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.